package com.hmdp.utils;

import cn.hutool.core.lang.UUID;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;

import java.util.Collections;
import java.util.concurrent.TimeUnit;

public class SimpleRedisLock implements ILock{
    private String name;//锁的名称，跟业务有关
    private StringRedisTemplate stringRedisTemplate;

    public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.name = name;
        this.stringRedisTemplate = stringRedisTemplate;
    }

    private static final String KEY_PREFIX="lock";
    private static final String ID_PREFIX= UUID.randomUUID().toString(true)+"-";

    private static final DefaultRedisScript<Long> UNCLOCK_SCRIPT;

    static{
        UNCLOCK_SCRIPT=new DefaultRedisScript<>();
        UNCLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
        UNCLOCK_SCRIPT.setResultType(Long.class);
    }

    @Override
    public boolean tryLock(long timeoutSec) {
        //获取线程标识
        String threadId = ID_PREFIX+Thread.currentThread().getId();
        //获取锁
        Boolean success =
                stringRedisTemplate.opsForValue()
                        .setIfAbsent(KEY_PREFIX+name,threadId , timeoutSec, TimeUnit.SECONDS);

        return Boolean.TRUE.equals(success);
    }

    @Override
    public void unlock(){

        //调用lua脚本
        stringRedisTemplate.execute(UNCLOCK_SCRIPT, Collections.singletonList(KEY_PREFIX + name),
                ID_PREFIX+Thread.currentThread().getId());
    }

//    @Override
//    public void unlock() {
//        //获取线程标识
//        String threadId = ID_PREFIX+Thread.currentThread().getId();
//        //获取锁的标识
//        String id = stringRedisTemplate.opsForValue().get(KEY_PREFIX + name);
//        //判断标识是否一致
//        if(threadId.equals(id)){
//            //释放锁
//            stringRedisTemplate.delete(KEY_PREFIX+name);
//        }
//
//    }
}
